Method for producing a nozzle-load for a water cooled blowing lance

ABSTRACT

The disclosure relates to a nozzle-head for a water-cooled blowing lance comprising at least one outlet opening for a gaseous refining agent and, if desired, fine-grained fluxes, an inlet piece, at least one nozzle tube leading through a watercooled space and a front plate to which the at least one nozzle tube is connected, in which the improvement resides in that both the inlet piece and the front plate are provided with tubular projections which are connected with each other to form said nozzle tubes, the connection plane lying perpendicularly to the nozzle-head axis at a distance from the front plate amounting to about one-fourth to two-thirds of the height of the nozzle-head. The number of connecting seams corresponds to the number of nozzle tubes; the seams are far away from the front plate and thus sheltered from any danger to damage.

United States Patent [151 3,662,447 Schweng et al. 1 May 16, 1972 [54]METHOD FOR PRODUCING A NOZZLE- 2,397,084 3/1946 Bernhardt ..29/48l LOADFOR A WATER COOLED 3,228,612 H1966 Graham et al. BLOWING LANCE 3,477,11211/1969 Yerkins ..29/l57 C [72] Inventors: Otto Schweng; HellmuthSmejkal; Hans p E h R C b ll Vere); Karl of Ausma AssistantExaminer-Donald C. Reiley, 111 [73] Assignee: Vereinigte OsterreichischeEisenund A'mmeyKun Kelman Stahlwerke Aktiengesellscaft, Linz, Austria[57] ABSTRACT 22 Filed: Aug. 5, 1970 I The disclosure relates to anozzle-head for a water-cooled PP N03 61,090 blowing lance comprising atleast one outlet opening for a gaseous refining agent and, if desired,fine-grained fluxes, an 30 Foreign Application p Data inlet piece, atleast one nozzle tube leading through a watercooled space and a frontplate to which the at least one nozzle Aug. 14, 1969 Austria ..A 7830/69tube is connected in which the improvement resides in bat both the inletpiece and the front plate are provided with tubu- [52] g 2 29/501 larprojections which are connected with each other to form I t 3 53 6 igsaid nozzle tubes, the connection plane lying perpendicularly d /29/157C2 to the nozzle-head axis at a distance from the front plate 0 am zglblc239/132 amounting to about one-fourth to two-thirds of the height of thenozzle-head. The number of connecting seams cor- 56 responds to thenumber of nozzle tubes; the seams are far 1 References Cited away fromthe front plate and thus sheltered from any danger UNITED STATES PATENTSto damage- 2,378,516 6/1945 Timmerman et al ..29/l57 C 7 Claims, 8Drawing Figures 9 10 I I l a,

i: I 17 I8 "E i611 PATENTEDHAY 16 I972 SHEET 1 BF 2 FIG-7.2a (33 FIG. la

FIG. 2b

INVENTORS 0W0 SQHVIENC-a HeLLMuJH 5MIKAL Hans vea BY KHRL E\L R AGENTMETHOD FOR PRODUCING A NOZZLE-LOAD FOR A WATER COOLED BLOWING LANCE Theinvention relates to a nozzle-head for a water-cooled blowing lancecomprising one or several outlet openings for a gaseous refining agentand, if desired, fine-grained admixtures, an inlet piece, one or severalnozzle tubes leading through a water-cooled space and connected with afront plate, and to a method for producing such nozzle-head.

In basic oxygen steelmaking methods the oxygen necessary for refiningthe pig iron is blown onto the metal bath by means of water-cooledblowing lances. These blowing lances are provided at their lower endwith nozzle-heads usually made of oxygen-free electrolyte copper whichguarantees a long life of the nozzle-head because of the good heatconductivity and the poor affinity of copper to oxygen.

In the course of the development of basic oxygen methods at firstblowing lances with only a single outlet for oxygen and, if desired,fine-grained fluxes were used. As a rule, the blowing lances comprisedan oxygen supply tube and a nozzle-head, the outlet opening in thenozzle-head being preferably designed to be converging-diverging(Laval-nozzle). The nozzle-heads were produced from preforged blanks bychip removal. Later on, nozzle-heads with several outlets, so-calledmulti-hole nozzles, were used for larger converters; in this type ofnozzles the holes are arranged in a manner that their axes are inclinedto the blowing lance axis under a specific angle and the refining agentleaves these holes in several streams so that the reaction area of theoxygen with the melt is enlarged. Today, for most basic oxygenconverters multi-hole nozzles are used which have e.g. three, four, fiveor six outlet openings. At first the noule-heads for such blowing lanceswere manufactured exactly as those for the one-hole nozzles. It wasfound, however, that this manufacturing process was unsuitable becausethe medium part of the nozzle-head, the so-called star, is greatly wornas a result of insufficient cooling, which may lead to a leakage and anunfavorable blowing performance which again causes slopping of slag andmetal from the converter and a higher nitrogen content of the steel. Itwas realized that the nozzle-heads, which so far had been made of onepiece, had to be divided into several individual parts; these parts areproduced separately and then connected with each other by soldering orwelding soas to permit access of the cooling water to the individualnozzle tubes. The individual parts are primarily produced by forging sothat a finegranular structure is present in the material; cast partshave a coarse and porous structure and are unsuitable for thisapplication. In the method employed so far e.g. for the production of athree-hole nozzle, an inlet piece and a front plate are separatelymanufactured by drop forging whereupon these parts are worked by meansof chip removal and connected with each other via three interposedprefabricated nozzletubes by soldering or welding. This way ofmanufacturing necessitates exact working and fitting of the individualparts, soldering or welding is very time consuming, and great manualdexterity is needed because it is difficult to connect the nozzle tubes,which are arranged very closely side by side, with the front plate andthe inlet piece. The life of the multi-hole nozzles thus produced wasimproved but still it may happen that the nozzle-heads are ruinedprematurely owing to unavoidable faults in the manufacturing process. Aparticular disadvantage resides in that two partition planes are presentin that part of the nozzle-head which gets into contact with oxygen; ofthese planes one lies very closely to the surface of the front plate. Incase of flame erosion of the nozzle-head in the vicinity of the outletopenings it may happen that the soldering seam of this partition planegets undone which would result in a failure of the nozzle-head.

The invention is aimed at creating a new nozzle-head for oxygen blowinglances with one or sever 1 outlet openings with which thesedisadvantages and provided are avoided. Furthermore the invention isaimed at a method for producing such nozzle-head in a simple, safe andcheap way guaranteeing an improved, prolonged life.

' the nozzle-head.

Preferably a water deflecting body is resting on ribs of the frontplate, said body being provided with recesses whose number and shapecorresponds to the number and shape of the nozzle tubes, the walls ofsaid recesses surrounding the nozzle tubes for at least two-thirds oftheir circumference thus forming continuous annular cooling-watercanals.

The method according to the invention for the production of anozzle-head is characterized by the steps of: producing blanks for theinlet piece and the front plate each with studs in a numbercorresponding to the number of the nozzle tubes; providing for planarsurfaces at the end of the studs of either blank perpendicularly to thenozzle-head axis e.g. by milling, grinding, turning or the like;drilling equidistant holes parallel to the nozzle-head axis through thestuds of either blank in the area of the outlet opening to be made at alater point; if desired, arranging a prefabricated annular waterdeflecting body on the blank for the inlet piece; combining the blanksprovided with the holes and inserting preferably annular soldering foilsbetween the areas of contact of the stud ends of either blank; heatingthe blanks to soldering temperature and cooling them subsequently;mechanically working the blanks which are now soldered together, i.e.boring or drilling the outlet openings, working on the bevel edges forthe weld connection with the tubes of the blowing lance, milling agroove at the inlet piece and a supporting surface on the ribs of thefront plate; and, if desired, connecting the finished nozzle-headcomprising the inlet piece and the front plate with a blowing lance.

Suitably, the combined two blanks are put onto an auxiliary meanscomprising a plate and guiding pins vertically arranged thereto, saidguiding pins engaging into the holes of the blanks thus affordingcentering and fixing of these parts.

Preferably the two blanks for the inlet piece and the front plate and,if desired, the water deflection body are produced by drop forging frompressed material which was preforged in one or several heats,particularly copper, so that a high degree of shaping is achieved, whichamounts to about 5 to 25 fold, preferably 10 to 15 fold, shaping for theblank for the front plate.

The annular water deflection body may be composed of two parts.

In order that the invention may be more fully understood these andfurther features of the invention shall now be explained by reference tothe accompanying drawings.

FIG. 1 a is a vertical sectional view of a nozzle-head connected with ablowing lance according to the known construction and manufacturingtechnique, which was also employed by applicants so far.

FIG. 1 b is a horizontal sectional view along line I--] of FIG. 1 a.

FIG. 2 a is a vertical sectional view of the nozzle-head according tothe invention and FIG. 2 b is a horizontal sectional view along lineIIII of FIG. 2 a.

FIGS. 3 a, 3 b and 3 0 illustrate the method according to the inventionand show vertical sectional views of the blanks for the inlet piece andthe front plate, respectively, and of the water deflecting body.

FIG. 4 is a vertical sectional view through the blanks for the inletpiece and the front plate which are combined with the help of anauxiliary device according to a specific embodiment of the methodaccording to the invention.

The nozzle tip which belongs to the art and is shown in FIG. 1 acomprises a nozzle-head 1 which gets into contact with the refiningagent, and comprises a water deflecting ring 2 forming a separateconstructional part which guides the cooling water to the nozzle-head l.The nozzle-head 1 comprises an inlet piece 3, three individual nozzletubes 4 and the front plate 5 which parts are rigidly connected witheach other by soldering or welding. The axes of the nozzle tubes 4 areinclined towards the vertical line. In the water deflecting ring 2recesses 6 are provided; annular canals are formed between the walls ofthese recesses and the nozzle tubes 4 through which canals cooling waterflows with high speed in the direction shown by the arrows in FIG. 1 a,i.e. in downward direction toward the front plate 5. The individualparts 3, 4, 5 of the nozzle-head l are connected with each other at sixjunctures (there are three junctures at 7 and three at 8); the threejunctures 7 lie in planes close to the surface of the front plate 5 andtherefore they are in great danger when the nozzle-head is used in aconverter. As may be seen from FIG. 1 a it is extremely difficult tosolder or weld the conical nozzle tubes 4 which have to be very closelyspaced to the front plate 5 and the inlet piece 3 so as to have aleak-proof connection all around. The nozzle-head 1 is welded orsoldered via its inlet piece 3 to the oxygen tube 9 of the blowing lanceand via its front plate 5 with the jacket tube 11. Between the tubes 9and 11 a water guiding tube is built in which is rigidly connected withthe water deflecting ring 2 which is supported on ribs of the frontplate 5 so that the front plate is intensively cooled, too. Particularlyendangered zones of the front plate 5 are the middle part (star) denotedwith numeral 12 and the edges 13 in the area of the outlet openings 14for the oxygen.

FIG. 2 a shows for ready comparison the nozzle-head according to theinvention. The nozzle-head 1' comprises only two parts, i.e. the inletpiece 3' with tubular projections 17 and a front plate 5 with tubularprojections 16; thus, only three junctures 18 are present which are at agreat distance from the surface of the front plate 5' and are lying inone plane, which is perpendicular to the axis 33 of the nozzlehead. Thisconnection cannot come undone owing to the influence of heat because theconnecting areas are in about the middle of the nozzle-head 1'. It issuitable to arrange the planes of the junctures 18 at a distance fromthe surface of the front plate 5' amounting to from one-fourth toone-third of the height of the nozzle-head 1'. The ring 2' around whichthe water circulates is provided with recesses 6 surrounding the tubes16 through about two-thirds of their circumference, thus formingcontinuous annular canals; in FIG. 2a the current of the water isillustrated by arrows. The speed with which the water circulates throughthe nozzle-head is continuously increased in the area of the ring 2 toreach a maximum when the water enters the space defined by the tubes l0,11. The baffle ring 2' rests on narrow ribs 15' (FIG. 21:). Preferablythe ring 2' consists of one piece. In the area of the inlet piece 3' agroove or notch 20 is provided for engaging adjusting screws 19 forcentering the water guiding tube 10 relative to the oxygen tube 9.

FIG. 3 a shows a blank 21 for the inlet piece 3' which blank is dropforged from a preformed block in one or two heats. The blank 21 isprovided with three conical studs 22 whose outer shape corresponds tothe tubularprojections 17. FIG. 30

shows a blank 25 for the front plate 5, which blank 25 is formed in thedie from a block which is preformed in one or two heats; in this processa 5 to 25 fold total shaping is to take place; a preferably 10 to 15fold shaping is necessary in order to obtain a fine-granular and densestructure. The blanks 21, 25 are preferably made of oxygen-freeelectrolyte copper. In principle, it is, however, possible to use alsoother metals, e.g. pure nickel or stainless steel for producing them.The blanks 21 25 have an outer shape which makes it possible to form thenecessary bevel edges 24, 24 and the groove 20 for connecting thenozzle-head with the blowing lance and for engagement of the adjustmentscrews 19, respectively, at a later point. In FIGS. 3 a and 3 c theinner contours of the tubular projections l6, 17 is shown in dottedlines. After forging, at the ends of the studs 22, 26, planar surfaces28, 28' are produced which are perpendicular to the axis 33 of thenozzlehead, and central holes 23, 23' are driven in, so that bores '29(FIG. 4) may be produced going through the studs 22, 26. In FIG. 3 b thewater deflecting ring 2', which is preferably made of steel in onepiece, is shown. This ring 2' lies on the supporting surfaces 27 (FIG. 3c) of the ribs 15' of the front plate 5' when the nozzle-head is joinedto the blowing lance.

FIG. 4 shows an auxiliary device for joining the blanks 21, 25 whichdevice comprises a plate 30 and vertically arranged guiding pins 32.Previously, holes 29 had been bored into the blanks through the studs22, 26 within the predetermined, inner contour of the tubularprojections l7, 16, which is shown in dotted lines. The guiding pins 32engage in these holes 29 and represent a centering means for the blanks25, 21. Between the partition planes 28, 28' a solder in the form of anannular solder foil is inserted, whereupon heating to solderingtemperature of about 700 to 900 C in a temperature controlled furnacetakes place. Then the blanks are cooled slowly to obtain a firmsoldering connection between the blanks 21, 25. If, as shown in FIG. 4,a water circulating ring 2' is used made of one piece, it is insertedafter the blank 21 is put onto the auxiliary device comprising the plate30 and the guiding pins 32 whereupon the blank 25 is joined with theblank 21. After the blanks 21, 25 are soldered, the auxiliary means isremoved and mechanical working is started, i.e. the milling or boring,respectively, of the insides of the tubular projections l6, 17, thebevel edges 24, 24, the groove 20 and the support planes 27 (FIG. 3 a or3 c, respectively). The finished nozzlehead 1' together with the watercirculating ring may then be welded with the tubes 9, 10, ll of theblowing lance; adjusting screws 19 help to carry out centering of thetube 10.

What we claim is:

1. In a method for producing a nozzle-head for a blowing lance,comprising at least one outlet opening for a gaseous refining agent, aninlet piece, at least one nozzle tube leading through a water-cooledspace, and a front plate to which said at least one nozzle tube isconnected, the steps of a. producing blanks for the inlet piece and thefront plate each with studs in a number corresponding to the number ofnozzle tubes;

b. providing for planar surfaces at the ends of the studs of eitherblank perpendicularly to the nozzle-head axis;

c. drilling equidistant holes parallel to the nozzle-head axis throughthe studs of either blank in the area of the outlet openings to be madeat a later point;

d. uniting the blanks provided with the holes and inserting solderingfoils between the areas of contact of the stud ends of either blank;

. heating the blanks to soldering temperature and cooling themsubsequently;

f. mechanically working the blanks soldered together, in-

cluding operations of drilling the outlet openings and forming beveledges for the connection with the blowing lance.

2. The method set forth in claim 1, wherein said blank for said frontplate is formed with ribs, a prefabricated annular water deflecting bodydesigned to rest on said ribs is arranged on the blank for the inletpiece before the blanks are combined, and said ribs are machined toprovide for a support surface for said annular body.

3. The method set forth in claim 1, wherein the finished nozzle-headcomprising the inlet piece and the front plate is connected with ablowing lance.

4. The method set forth in claim 1, wherein a peripheral groove ismilled in the inlet piece for engagement therewith of adjusting screwsserving as centering means when said nozzlehead is connected with ablowing lance.

5. The method set forth in claim 1, wherein the combined two blanks areput onto an auxiliary means comprising a plate and guiding pinsvertically projecting therefrom, said guiding pins engaging the holes ofthe blanks thus affording centering and fixing of said blanks.

6. The method set forth in claim 1, wherein the two blanks for thesupply piece and the front plate are produced by drop forging frompressed metal which was pre-forged in at least one heat so that a highdegree of shaping is achieved, namely an about 5 to 25 fold shaping ofthe blank for the front plate.

7. The method set forth in claim 1, wherein the water deflection body isalso made by drop forging. 5

1. In a method for producing a nozzle-head for a blowing lance,comprising at least one outlet opening for a gaseous refining agent, aninlet piece, at least one nozzle tube leading through a water-cooledspace, and a front plate to which said at least one nozzle tube isconnected, the steps of a. producing blanks for the inlet piece and thefront plate each with studs in a number corresponding to the number ofnozzle tubes; b. providing for planar surfaces at the ends of the studsof either blank perpendicularly to the nozzle-head axis; c. drillingequidistant holes parallel to the nozzle-head axis through the studs ofeither blank in the area of the outlet openings to be made at a laterpoint; d. uniting the blanks provided with the holes and insertingsoldering foils between the areas of contact of the stud ends of eitherblank; e. heating the blanks to soldering temperature and cooling themsubsequently; f. mechanically working the blanks soldered together,including operations of drilling the outlet openings and forming beveledges for the connection with the blowing lance.
 2. The method set forthin claim 1, wherein said blank for said front plate is formed with ribs,a prefabricated annular water deflecting body designed to rest on saidribs is arranged on the blank for the inlet piece before the blanks arecombined, and said ribs are machined to provide for a support surfacefor said annular body.
 3. The method set forth in claim 1, wherein thefinished nozzle-head comprising the inlet piece and the front plate isconnected with a blowing lance.
 4. The method set forth in claim 1,wherein a peripheral groove is milled in the inlet piece for engagementtherewith of adjusting screws serving as centering means when saidnozzle-head is connected with a blowing lance.
 5. The method set forthin claim 1, wherein the combined two blanks are put onto an auxiliarymeans comprising a plate and guiding pins vertically projectingtherefrom, said guiding pins engaging the holes of the blanks thusaffording centering and fixing of said blanks.
 6. The method set forthin claim 1, wherein the two blanks for the supply piece and the frontplate are produced by drop forging from pressed metal which waspre-forged in at least one heat so that a high degree of shaping isachieved, namely an about 5 to 25 fold shaping of the blank for thefront plate.
 7. The method set forth in claim 1, wherein the waterdeflection body is also made by drop forging.